Direct Centroidal Control for Balanced Humanoid Locomotion

TL;DR

This paper introduces a real-time, integrated control method for humanoid robot locomotion based on direct centroidal control, enabling natural gait and balance with minimal sensor requirements.

Contribution

It presents a novel approach using simplified models for real-time centroidal control, improving humanoid gait naturalness and robustness with high portability.

Findings

Successfully demonstrated natural-looking gait with stretched-leg motion

Enabled effective push rejection during locomotion

Achieved high portability across different humanoid robots

Abstract

We present an integrated approach to locomotion and balancing of humanoid robots based on direct centroidal control. Our method uses a five-mass description of a humanoid. It generates whole-body motions from desired foot trajectories and centroidal parameters of the robot. A set of simplified models is used to formulate general and intuitive control laws, which are then applied in real-time for estimating and regulating the center of mass position and orientation of the multibody's principal axes of inertia. The combination of proposed algorithms produces a stretched-leg gait with naturally looking upper body motions. As only a 6-axis IMU and joint encoders are necessary for the implementation, the portability between robots is high. Our method has been experimentally verified using an igus Humanoid Open Platform, demonstrating whole-body locomotion and push rejection capabilities.